package base;
import jm.audio.AOException;
import jm.audio.AudioObject;
import jm.audio.io.SampleOut;
import jm.audio.synth.*;

/**
 * A basic FM synthesis instrument implementation
 *
 * @author Andrew Sorensen
 */

public final class SimpleFMInst extends jm.audio.Instrument {
    //----------------------------------------------
    // Attributes
    //---------------------------------------------
    /**
     * The number of channels
     */
    private int channels;
    /**
     * The modulation index
     */
    private int modIndex;
    /**
     * The frequency ratio from the carrier frequency (the notes pitch)
     */
    private float frqRatio;

    private int sampleRate;

    //----------------------------------------------
    // Constructor
    //----------------------------------------------

    /**
     * Basic default constructor to set basic values
     *
     * @param sampleRate The instrument's audio resolution
     * @param modIndex   The modulation index, greater = more overtones
     * @param ratio      The carrier/modulator pitch ratio = harmonicity of spectrum
     */
    public SimpleFMInst(int sampleRate, int modIndex, double ratio) {
        this(sampleRate, modIndex, ratio, 1);
    }

    /**
     * A constructor to set all values
     *
     * @param sampleRate The instrument's audio resolution
     * @param modIndex   The modulation index, greater = more overtones
     * @param ratio      The carrier/modulator pitch ratio = harmonicity of spectrum
     * @param channels   The number of channels
     */
    public SimpleFMInst(int sampleRate, int modIndex, double ratio, int channels) {
        this.sampleRate = sampleRate;
        this.channels = channels;
        this.modIndex = modIndex;
        this.frqRatio = (float) ratio;
    }

    //----------------------------------------------
    // Methods
    //----------------------------------------------

    /**
     * Initialisation method used to build the objects that
     * this instrument will use
     */
    public void createChain() throws AOException {
        // modulator
        Oscillator modulator = new Oscillator(this, Oscillator.SINE_WAVE, this.sampleRate, this.channels);
        modulator.setFrqRatio(frqRatio);
        modulator.setAmp((float) modIndex);
        Envelope env = new Envelope(modulator, new double[]{0.0, 1.0, 1.0, 0.0});

        // constant
        Value constFreq = new Value(this, this.sampleRate, this.channels, Value.NOTE_PITCH);
        Add add = new Add(new AudioObject[]{constFreq, env});

        // carrier
        Oscillator carrier = new Oscillator(add, Oscillator.SINE_WAVE, Oscillator.FREQUENCY);
        Envelope ampEnv = new Envelope(carrier, new double[]{0.0, 0.0, 0.02, 1.0, 1.0, 0.0});
        Volume amp = new Volume(ampEnv);
        StereoPan pan = new StereoPan(amp);
        SampleOut sout = new SampleOut(pan);
    }
}

